Old Post but here's some input. In certain areas of Scotland (Fraserburgh, Peterhead, Banff, Buchan, Buckie for example and the West Coast - Gaeltacht), because names repeat through a family based on a typical if not rigid naming pattern (first son - pat. g/father, first daughter - mat. g/mother etc), there is a custom, or practice of referring to people by two first names.
So you get Donald John, John Angus, Angus Brendan, Davie Robert, Margaret Anne, Jean Mary, Agnes Ishbell etc.
And of course, you get Big Davie, Young (or Wee) Davie and in Gaelic there is the byname by descriptor, Domhail Dubh or by job, (Donald the Hotel, cf Padraig Post) different Alexanders might be variously Sandy, Young Sandy, Eck, Eckie, Auld Alec. This - especially the nicknames/ vareity of diminutives within a family might - is especially true of women's names, so there is Maggie, Peigi, Meg, Magret, or Ishbel, Tib, Tibby, Bella, Belle plus any other descriptors. Even now one might speak of Harbour Kate, bicycle Kate, Margaret's Kate etc.
Separately there was also the practice in some parts where land owners and also tenant farmers were known by the land they owned/worked, so Lord John Gordon (in the ballad, Glenlogie) is also known as Glenlogie while the other character in the ballad, Jeannie Melville, is also referred to as Jeannie of Bethelnie, and in the 70s/80s, soap, Take the High Road, one of the characters, Tam Kerr was known as Inverdarroch from the farm he worked. In another ballad, Belle is known as Bogie's Bonnie Belle, from her father's land/farm.
Yes, there is/was also the tradition of using the child's grandparent's (or mother's) maiden name as middle names, alongside this (but maybe in different areas of the coutnry).
Sometimes this developed into people being known as (J[ohn]) Forbes Meldrum, or (A[llan]) Grant MacDonald; though not among women. Neil Munro's novel, "The Daft Days" starts from a point of confusion where the relative coming to stay from Chicago, Lennox, is presumed to be a boy child, not a girl.